How to Install a Power Steering Box In a Chevy C10

The Chevy C10’s factory steering box uses a 16:1 ratio, requiring at least 4 full turns to get from lock to lock. While that was fine back when the trucks first rolled off the lot, modern times call for modern steering. This guide will walk you through the steps of upgrading the steering box in your 1968-1986 C10.

Pre-Installation Considerations

Before you dive into the installation, consider the following:

• Are you going to remove the wheel? Removing the driver-side front wheel isn’t necessary, but could give a better view for the install.
• How old are your steering components? Now would be a great time to replace your pitman arm, fluid lines, and any other steering parts that are rusty or worn out.
• Is your stock rag joint going to fit? Depending on the box you choose, you might have to replace your rag joint. Our C10 is a pre-1977 model and needed a new joint to be compatible with the ¾” input shaft on the Borgeson power steering box we installed.

Power Steering Box Installation

For our replacement, we went with the Borgeson Street and Performance power steering box. The Borgeson unit uses a 12.7:1 quick-ratio that shortens lock-to-lock steering wheel turns from 4 to 2-½ for better steering response.

The steering box you choose should come with its own installation instructions, so be sure to reference them along with this how-to when you’re working on your C10.

Required Tools:

• 5/8” Wrench
• 11/16” Wrench
• 3/4” Socket
• 3/8” Ratchet
• 5/36” Allen Key
• 1/2” Wrench
• 1/2” Socket
• Pitman Arm Puller
• Drip Pan
• Hammer
• Steering Fluid
• Frame Rail Paint

Step 1: Lift Your Truck

Lift your truck with either a full lift or a jack and jack stands. If you want to remove the driver-side front wheel for a better view, now is the time.

Step 2: Remove Power Steering Fluid Lines

Position your drain bucket under the steering box. Remove the front line with a ⅝” wrench and the rear line with an 11/16” wrench. Let them both empty into the drip pan.

Step 3: Disconnect Power Steering Shaft

Remove the 7/16” bolt connecting the rag joint to the steering box. Once you remove the bolt, tap the steering shaft with a hammer to disconnect it from the steering box.

Step 4: Remove Brace

Using a ¾” socket and wrench, remove the brace behind the steering box. This frees up space for a smooth and easy box swap.

Step 5: Remove Power Steering Pitman Arm

Remove the bottom nut holding the pitman arm in place. Use a pitman arm puller to free the arm from the steering box.

Step 6: Remove Steering Box

Remove the four ⅝” socket bolts holding the steering box in place. These bolts are best accessed from the inside of the frame rail. Once the bolts are out, pull the box off the pitman arm and steering shaft and set it aside.

Pro Tip: Instead of throwing your old steering box away, make a little cash by selling it. People are always looking for original C10 parts. If you can’t find a buyer, you can always make some money by selling it at a recycling center.

Step 7: Clean and Prep Frame Rail for New Box

Remove the grease, dirt, and grime on the frame rail left from the old steering box and apply a fresh coat of paint. This is a preventive measure that will protect your rail from rust and corrosion.

Step 8: Install New Box Into Pitman Arm

Guide your new steering box into the pitman arm. Once it’s in place, position the box so the input shaft is facing the rag joint.

Step 9: Change Rag Joint to Fit 3/4" Input Shaft (If Necessary)

If your C10’s rag joint doesn’t fit the ¾” input shaft, you will need to replace it with the correct size.

Remove the two ½” bolts on your rag joint using a ½” wrench and socket and pull the old rag joint off. Align the holes on the new rag joint to the holes on the steering shaft and reinstall the ½” bolts.

Step 10: Attach Box to Rag Joint

Slip the ¾” input shaft into the new rag joint. Tighten the set screw with a 5/32” allen key and then tighten down the jam nut with a ½” socket.

Step 11: Reinstall Steering Box Bolts on Frame Rail

Reinstall the steering box bolts from the inside of the frame rail.

Step 12: Reinstall Pitman Arm Nut and Washer

Tighten the pitman arm nut to set the arm in place. Remove the nut again, add the lock washer, and tighten down the pitman arm nut.

Step 13: Reinstall Power Steering Hoses

If you’re using the factory lines, use the included adapters to fit them into the new power steering box.

If you’re using aftermarket lines, they should fit into the box without the included adapters.

Attach the larger line to the back of the box and the smaller line to the front. Tighten both lines back in place with their respective wrench sizes.

Step 14: Refill Power Steering Fluid

Reinstall the brace you removed in Step 4, then lower your truck off the lift or jack stands. Refill your power steering fluid, taking care to leave room at the top for the fluid to settle.

Try Out Your New Steering Box

Get behind the wheel and give it a few turns. Your new steering box should only need 2-3 turns of the wheel to get from lock to lock. If everything feels smooth, you’re ready to enjoy modern truck handling in your classic C10.

Consider adding a set of sway bars and other C10 suspension upgrades to get more performance out of your new box.